|  | 6.7 | Placing ACLs
| 6.7.2 | Using ACLs in firewall routers

ACLs should be used in firewall routers, which are often positioned between the internal network and an external network, such as the Internet. The firewall router provides a point of isolation so that the rest of the internal network structure is not affected. You can also use ACLs on a router positioned between two parts of the network to control traffic entering or exiting a specific part of the internal network. To provide the security benefits of ACLs, you should at a minimum configure ACLs on border routers, which are routers situated on the boundaries of the network. This provides basic security from the outside network, or from a less controlled area of the network, into a more private area of the network. On these border routers, ACLs can be created for each network protocol configured on the router interfaces. You can configure ACLs so that inbound traffic, outbound traffic, or both are filtered on an interface.
| Threaded Case Study
| Washington Project: Firewall Implementation The Internet connectivity you will need to implement in the Washington School District requires a double firewall implementation, with all the applications that are exposed to the Internet residing on a public backbone network. You need to ensure that all connections initiated from the Internet into each school's private network will be refused.